Functional role of ectomycorrhizae on drought resistance and recovery of beech and spruce

外生菌根对山毛榉和云杉抗旱和恢复的功能作用

• 批准号: 394182657
• 负责人: Professor Dr. Thorsten Grams
• 金额: --
• 依托单位: Lehrstuhl für Ökophysiologie der Pflanzen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/394182657?language=en
• 关键词: Functional; role; ectomycorrhizae; drought; resistance

In the previous funding term, we found structure and functions of ectomycorrhizal (ECM) communities of to be gradually changed during three summer droughts imposed in a throughfall exclusion experiment at Kranzberg Forest (TEE). Drought effects on ECM communities of Picea abies (L.) Karst. were stronger than on ECM of Fagus sylvatica (L.) but only after three repeated drought years. Increasing drought frequency reduced vital fine roots and ECM community diversity, but not hydrolytic enzyme activities. Tree mixture positively influenced ECM diversity and fine root vitality even under extreme water limitation. A relative increase in long-distance type ECM and no increase of EA with saprotrophic potential under drought support current concepts that question C- limitation in trees upon drought. The actual synthesis of results on ECM diversity and functions suggests correlations to vary depending on a given context of drought specific tree species reactions varying with monospecific/mixed interaction zone and soil depth. This high context dependency for survival of ECM requires further clarification. Therefore, a major objective in this follow up proposal is to better link above- and belowground processes upon drought resistance and recovery. Therefore this joint proposal of plant ecophysiologist and mycorrhizal ecologist aims to connect the rather contrasting above-ground drought responses of beech and spruce with below-ground differences in C supply under drought and to sinks upon re-watering. A phytotrone experiment is performed in the context of differently adapted ECM communities from different soil origins (moist vs. dry sites along a Bavarian precipitation gradient), and in parallel the unique conditions of the Kranzberg Forest TEE represents a relevant scenario on adult forest trees. 13C labeling in these experiments will allow addressing quantitatively C-allocation to sinks. For this purpose we will assess reactivity of ECM under drought and upon re-watering particularly the effect of mixture on attenuation of drought impact on ECM communities. This will be connected with tree sensitivity of and resource fluxes (C, H2O, N) among intra- and interspecifically grown beech and spruce under drought and subsequent recovery in differently adapted soils. We assess plant structural, physiological, biochemical parameters and use stable isotope labelling (13C, 15N, D2O). ECM community structure will be analyzed combined with functional parameters. A focus will be on parameters related to carbon relations of plant roots with fungi (invertase/amylase activity, composition of non-structural hydrocarbons (NSC)). The expected outcome of the proposal is clarification of 1) soil impact on drought response of trees, 2) effects of mixture upon drought reactions of tree species and their ECM communities, and 3) differences in drought recovery of beech and spruce upon re-watering.

在上一个资助期，我们发现外生菌根（ECM）社区的结构和功能逐渐改变，在三个夏季干旱期间施加在穿透雨排除实验在克兰茨贝格森林（TEE）。干旱对欧洲云杉ECM群落的影响喀斯特比在欧洲山毛榉（Fagus sylvatica（L.）但仅仅是在连续三年干旱之后。增加干旱频率降低重要的细根和ECM群落多样性，但不水解酶活性。树木混合积极影响ECM多样性和细根活力，即使在极端水分限制。长距离型ECM的相对增加，没有增加的EA与腐殖潜力干旱支持目前的概念，问题C-限制在树木干旱。ECM多样性和功能结果的实际综合表明，相关性会根据干旱特定树种反应的特定背景而变化，该反应随单种/混合相互作用区和土壤深度而变化。ECM存活的这种高度上下文依赖性需要进一步澄清。因此，本后续行动建议的一个主要目标是更好地将地上和地下抗旱和恢复进程联系起来。因此，植物生态生理学家和菌根生态学家的这一联合提案旨在将山毛榉和云杉的地上干旱反应与干旱下地下C供应的差异以及重新浇水后的汇联系起来。植生室实验进行的背景下，不同的土壤来源（潮湿与干燥的网站沿着巴伐利亚降水梯度），不同适应ECM社区，并在平行的独特条件的克兰茨贝格森林TEE代表一个相关的情况下，成年林木。在这些实验中的13 C标记将允许定量地解决C-分配到汇。为此，我们将评估ECM在干旱和复水时的反应性，特别是混合物对ECM群落干旱影响衰减的影响。这将与树的敏感性和资源通量（C，H2O，N）之间的内部和种间生长的山毛榉和云杉干旱和随后的恢复在不同的适应土壤。我们评估植物的结构，生理，生化参数，并使用稳定同位素标记（13 C，15 N，D2 O）。ECM群落结构将结合功能参数进行分析。一个重点将是与植物根与真菌（转化酶/淀粉酶活性，非结构烃（NSC）的组成）的碳关系的参数。该提案的预期成果是澄清1）土壤对树木干旱反应的影响，2）混合物对树种及其ECM群落干旱反应的影响，以及3）重新浇水后山毛榉和云杉干旱恢复的差异。